| 摘要 |
<p>RECIPROCATING MACHINE WITH BOTH PRIMARY AND SECONDARY COUNTER ROTATING BALANCERS This invention relates to reciprocating machines with both primary and secondary counter rotating balancers wherein, an ordinary crankshaft has one or more crank throws and each crank has a connecting rod driving a reciprocating piston, and a contraweight is mounted at each end of the crankshaft and these rotate around the crankshaft in opposite directions of rotation from that of the crankshaft but at the same RPM as the crankshaft, and the contraweights in cooperation with main counterweights (on the crankshaft) balance the primary reciprocating inertia forces, and two countershafts (being parallel to the crankshaft) carry secondary balance weights and rotate in opposite directions at twice the RPM of the crankshaft so as to counterbalance the secondary reciprocating inertia forces, and the two countershafts also serve as a transmission and reversor for driving the two said contraweights so as to minimize the total number of gears, shafts, and bearings, and the two countershafts and the two contraweights are all intergeared to the crankshaft. INTRODUCTION AND GENERAL NATURE OF THIS INVENTION A basic problem with reciprocating machines is that there are unbalanced shaking forces as illustrated in Figs. 1 and 2. A good application of this invention would be in a large single crank double acting compressor machine. Another application would be a large in-line reciprocating machine of one to three or possibly more cylinders. The following formula is for the accelleration of a piston in a crank-connecting rod mechanism. This formula can be found in most text books on the kinematics of machinery. accelleration = r.omega.2 (cos .THETA. ? cos 2.THETA./N) where accelleration = centimeters per second per second r = crank radius or throw centimeters .omega. = rotational speed - radians per second e = angle in degrees that the crankarm has advanced from the top dead center position. N = ratio of connecting rod length to crank throw. The well known formula relating inertia force and accelleration is: reciprocating inertia force = weight x accelleration/gravity</p> |
